书城教材教辅科学读本(英文原版)(套装1-6册)
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第171章 第二册(88)

"I must not let you scratch mother"s nice spoon," he added, "but you could easily do it with a knife, for silver is a very soft metal. Pure silver would not be fit for use. It is too soft and would wear away. This spoon itself is not all silver; neither is this shilling. Some copper is always mixed with the silver to make it hard enough.""Don"t let us forget those thin leaves of silver that teacher showed us," said Will. "Why, they wereso thin you could blow them away, Norah. They were ever so much thinner than the tin-foil. You know that a thousand leaves of tin-foil, one on the other, make a pile an inch high. But you would want just ten thousand of these silver leaves to make a pile that height.""Then," said Norah, "what a very malleable metal silver must be.""It is," said Fred. "Teacher says it is more malleable than any of the common metals. It is so easily malleable,that it can be beaten into any shape, for making spoons, forks, trays, cups, tea and coffeepots, andmany other things for use and ornament, as well as the money, with which we buy what we want.